Patent Application
20230382805
The present disclosure belongs to the technical field of refractory materials, and specifically relates to a sintering-resistant material, and a preparation method and use thereof.
Scrapped power batteries are a very important reusable resource. It is estimated that the quantity of scrapped power batteries in China will exceed 600,000 tons by 2025 and will exceed 1.5 million tons by 2030, which shows an exponential growth trend. Therefore, due to the continuous generation of scrapped power batteries, the scrapped power battery recycling industry will flourish. Contemporary Amperex Technology Co., Limited (CATL), Shanghai Automotive Industry Corporation (SAIC) Motor, Green Eco-manufacture (GEM), Build Your Dreams (BYD), Huayou Cobalt, and other companies have entered the scrapped power battery recycling industry chain.
At present, the fire-wet recycling technology is the mainstream recycling technology for scrapped power batteries, and includes the following steps: dismantling, discharging, crushing, roasting, screening, leaching, impurity removal, extraction, synthesis, and the like, which mainly aims to recover heavy metal elements such as nickel, cobalt, manganese, and lithium in scrapped power batteries and by-products such as aluminum, copper, iron, and graphite. However, when cathode materials of scrapped power batteries are roasted, a considerable proportion of organic solvents such as polyvinylidene fluoride (PVDF), ethylene carbonate (EC), dimethyl carbonate (DMC), lithium hexafluorophosphate (LHFP), lithium tetrafluoroborate (LTFB), and lithium hexafluoroarsenate (LHFA) in the scrapped power batteries is decomposed at a high temperature to produce harmful substances, which directly affect the recycling equipment, and cause particularly obvious damage to sintering-resistant materials in direct contact with battery active materials especially under the conditions of high temperature, high pressure, complex reaction, and the like.
Sintering-resistant materials for the recycling of scrapped power batteries are mostly SiC composite materials, high-MgO materials, and SiO2—Al2O3 materials, and the substances produced from the high-temperature decomposition of the organic solvents can easily react with MgO, Al2O3, and SiO2 to make a sintering-resistant material of a rotary kiln corroded and penetrated, thereby causing the sintering-resistant material to fall off and crack. At a high temperature, some reaction principles can be expressed by the following reaction equations:
LiPF6→PF5+LiF
LiPF6+H2O→OPF3+LiF+2HF
LiF+H2O→HF+Li2O
2HF+MgO→MgF2+H2O
4HF+SiO2→SiF4+2H2O
SiC+4HF→SiF4+CH4
6HF+Al2O3→2AlF3+3H2O
Moreover, the annual discharge of electric furnace slags from smelting in China exceeds 30 million tons. Generally, the electric furnace slags are deeply buried, processed into building materials, and dumped in the open air, and thus the comprehensive utilization of electric furnace slags is low. It is relatively rare to prepare a sintering-resistant material using metals extracted from an electric furnace slag and use the sintering-resistant material for the recycling of scrapped power batteries.
The present disclosure is intended to solve at least one of the technical problems existing in the prior art. In view of this, the present disclosure provides a sintering-resistant material, and a preparation method and use thereof.
According to one aspect of the present disclosure, a sintering-resistant material is provided, including the following raw materials: magnesium oxide, an anti-corrosive agent, an antioxidant, and a binder, where the anti-corrosive agent includes a barite powder and a porous graphite powder; the antioxidant includes aluminum carbide and an aluminum powder; and the binder includes a metal chloride and a silica sol.
In some implementations of the present disclosure, the magnesium oxide, the anti-corrosive agent, the antioxidant, and the binder may be at a mass ratio of (80-150):(1-15):(1-10):(0.1-10) and preferably 110:3.5:2.0:2.5.
In some implementations of the present disclosure, a mass ratio of the barite powder to the porous graphite powder may be (80-150):(1-10) and preferably (100-120):(7-10).
In some implementations of the present disclosure, a mass ratio of the aluminum carbide to the aluminum powder may be (20-100):(1-30). The aluminum carbide has relatively strong oxidation resistance, and the aluminum carbide has a large proportion in the antioxidant, which enhances the oxidation resistance of the sintering-resistant material.
In some implementations of the present disclosure, a mass ratio of the metal chloride to the silica sol may be 10:(1-5); and the metal chloride may be one or more from the group consisting of iron chloride, chromium chloride, zinc chloride, cobalt chloride, and nickel chloride.
The present disclosure also provides a preparation method of the sintering-resistant material described above, where metals in the raw materials are all extracted from an electric furnace slag, and the preparation method specifically includes the following steps:
In some implementations of the present disclosure, a solid-to-liquid ratio of the electric furnace slag powder to the hydrochloric acid may be 10:(40-80) (g/mL); and preferably, the hydrochloric acid may have a concentration of 8 mol/L to 12 mol/L. Further, the acid leaching may be conducted for 30 min to 40 min.
In some implementations of the present disclosure, after the acid leaching is completed and before the SLS, a slurry obtained by the acid leaching may be washed with hot water of 50° C. to 95° C., and a volume ratio of the slurry to the hot water may be 1:(7.5-10).
In some implementations of the present disclosure, the hydrogen chloride may be evaporated at 70° C. to 95° C. until a volume of the leachate is reduced by 200 ml/L to 400 ml/L.
In some implementations of the present disclosure, the aluminum hydroxide may be precipitated out at a pH of 3.0 to 4.8 and preferably 3.50; and the magnesium hydroxide may be precipitated out at a pH of 9.0 to 10.5 and preferably 9.40.
In some implementations of the present disclosure, the alkali liquor may be one or more from the group consisting of a sodium hydroxide solution, a potassium hydroxide solution, a magnesium hydroxide solution, and a calcium hydroxide solution, and the alkali liquor may have a concentration of 0.05 mol/L to 2 mol/L.
In some implementations of the present disclosure, the magnesium hydroxide and/or the chloride salt crystal may be subjected to dehydration for 30 min to 40 min at 180° C. to 300° C. The obtained magnesium oxide is anhydrous magnesium oxide.
In some implementations of the present disclosure, the reducing agent may be one or more from the group consisting of powdered carbon, pulverized coal, carbon monoxide, hydrogen, and hydrogen sulfide; and the reaction of the aluminum hydroxide with the reducing agent may be conducted at preferably 600° C. to 1,100° C. and more preferably 850° C. to 1,000° C.
In some implementations of the present disclosure, the aluminum may be ball-milled into an aluminum powder before reacting with the powdered carbon, and in the aluminum powder and/or the powdered carbon, more than 90% of particles may have a particle size of <300 μm and preferably <175 μm.
In some implementations of the present disclosure, the reaction of the aluminum with the powdered carbon may be conducted for 200 min to 400 min at 800° C. to 1,400° C. in a protective atmosphere; and a gas for the protective atmosphere may be one from the group consisting of argon, helium, and neon.
In some implementations of the present disclosure, more than 90% of the particles of the porous graphite powder and/or the barite powder may have a particle size of <150 μm and preferably <85 μm.
In some implementations of the present disclosure, the blank may be heated at 1,140° C. to 1,450° C. for 150 min to 450 min in an inert atmosphere, and an inert gas for the inert atmosphere may be one from the group consisting of nitrogen, helium, neon, and argon.
The present disclosure also provides use of the sintering-resistant material described above in the recycling of a scrapped power battery, which specifically refers to use in a sintering device for roasting a cathode material of a scrapped power battery. Further, the sintering device may be a rotary kiln.
According to a preferred implementation of the present disclosure, the present disclosure at least has the following beneficial effects:
The present disclosure is further described below with reference to accompanying drawings and examples.
The concepts and technical effects of the present disclosure are clearly and completely described below in conjunction with examples, so as to allow the objectives, features and effects of the present disclosure to be fully understood. Apparently, the described examples are merely some rather than all of the examples of the present disclosure. All other examples obtained by those skilled in the art based on the examples of the present disclosure without creative efforts should fall within the protection scope of the present disclosure.
In this example, a sintering-resistant material was prepared. The sintering-resistant material was composed of magnesium oxide, an anti-corrosive agent, an antioxidant, and a binder in a mass ratio of 110:4.5:2.0:2.5. The anti-corrosive agent was composed of a barite powder and a porous graphite powder in a mass ratio of 110:7.5; the antioxidant was composed of aluminum carbide and an aluminum powder in a mass ratio of 35:3.7; and the binder was composed of a metal chloride and a silica sol in a mass ratio of 10:1.2, and the metal chloride included iron chloride, chromium chloride, zinc chloride, cobalt chloride, and nickel chloride. As shown in
In this example, a sintering-resistant material was prepared. The sintering-resistant material was composed of magnesium oxide, an anti-corrosive agent, an antioxidant, and a binder in a mass ratio of 100:3.5:2.5:1.0. The anti-corrosive agent was composed of a barite powder and a porous graphite powder in a mass ratio of 100:7.5; the antioxidant was composed of aluminum carbide and an aluminum powder in a mass ratio of 33:6.1; and the binder was composed of a metal chloride and a silica sol in a mass ratio of 10:1.5, and the metal chloride included iron chloride, chromium chloride, zinc chloride, cobalt chloride, and nickel chloride. A specific preparation process was as follows:
In this example, a sintering-resistant material was prepared. The sintering-resistant material was composed of magnesium oxide, an anti-corrosive agent, an antioxidant, and a binder in a mass ratio of 120:5.5:2.5:3.5. The anti-corrosive agent was composed of a barite powder and a porous graphite powder in a mass ratio of 120:7.5; the antioxidant was composed of aluminum carbide and an aluminum powder in a mass ratio of 48:14.5; and the binder was composed of a metal chloride and a silica sol in a mass ratio of 10:1.8, and the metal chloride included iron chloride, chromium chloride, zinc chloride, cobalt chloride, and nickel chloride. A specific preparation process was as follows:
In this comparative example, a sintering-resistant material was prepared. In a preparation process of this comparative example, the silicon residue in step (1) was used instead of the magnesium oxide to prepare the sintering-resistant material; the steps (1) to (4) were the same as in Example 1; and the step (5) was specifically as follows:
In this comparative example, a sintering-resistant material was prepared. In a preparation process of this comparative example, the silicon residue in step (1) was used instead of 85 parts among the 110 parts of magnesium oxide to prepare the sintering-resistant material; the steps (1) to (4) were the same as in Example 1; and the step (5) was specifically as follows:
In this comparative example, a sintering-resistant material was prepared. In a preparation process of this comparative example, no antioxidant was added into the sintering-resistant material; the steps (1) to (4) were the same as in Example 1; and the step (5) was specifically as follows:
The sintering-resistant materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to a sintering-resistance test in a rotary kiln. During the test, 14 batches of electrode materials were roasted at 400° C. to 900° C.
It can be seen from Table 1 that Comparative Examples 1 and 2 have a lower compressive strength than the examples, and this is because Comparative Examples 1 and 2 include a large amount of silicon-based oxides, which reduces the compressive strength of the sintering-resistant material. A sintering reduction in Comparative Example 3 is significantly higher than that in the examples, resulting in a larger falling-off thickness, and this is because no antioxidant is added in Comparative Example 3, which makes the material more prone to oxidation, makes a structure of the material more likely to become brittle, and more of the material fall off after repeated roasting. In addition, Comparative Example 1 has a larger falling-off thickness and a greater reduction than Comparative Example 2, which indicates that the addition of a specified proportion of anhydrous magnesium oxide in the silicon residue as the main material can also improve the corrosion resistance and oxidation resistance to some extent.
The examples of present disclosure are described in detail with reference to the accompanying drawings, but the present disclosure is not limited to the above examples. Within the scope of knowledge possessed by those of ordinary skill in the technical field, various changes can also be made without departing from the purpose of the present disclosure. In addition, the examples in the present disclosure or features in the examples may be combined with each other in a non-conflicting situation.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110968476.4 | Aug 2021 | CN | national |
The present application is a continuation application of PCT application No. PCT/CN2022/093594 filed on May 18, 2022, which claims the benefit of Chinese Patent Application No. 202110968476.4 filed on Aug. 23, 2021. The contents of all of the aforementioned applications are incorporated by reference herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2022/093594 | May 2022 | US |
| Child | 18231798 | US |
